Although the ballot initiative is advisory only, it is expected to frustrate lawmakers mindful of public opinion as they face the court deadline next year.

Taiwan is set to hold a series of public votes on November 24 to decide whether same-sex unions should be written into law, raising uncertainty whether there will be full marriage equality on the island.

Constitution of Romania currently states that marriage is a union between "spouses". While the ruling could limit the definition of marriage, it would not preclude a law that would recognize same-sex civil partnerships

Marriage equality became law on December 9 with overwhelming support in Parliament, but Australia's requirement that all couples give a month's notice for weddings made Tuesday the first possible date for gay marriages.

Four countries, Malta, Germany, Finland and Australia legalised same-sex marriage in 2017. The first wedding in Australia will take place after a month when, the legislation shall take effect in the country.